Performance Evaluation of Xanthan Gum and Zeolite Additives on Fluid Loss in High-Temperature Water-Based Drilling Fluids

Abstract

In high-pressure, high-temperature (HPHT) drilling environments, conventional water-based drilling fluids often experience performance degradation due to viscosity reduction and fluid loss control. This study aims to evaluate the performance of xanthan gum (XG) and zeolite as environmentally friendly additives in enhancing thermal stability and filtration control of water-based drilling fluids. Zeolite–XG composites were synthesized using blending and grafting methods and tested under API and HPHT filtration conditions. Laboratory results showed that the mixing composite maintained the best performance, with the lowest fluid loss (84 mL/10 minutes at 500 psi) and stable mud cake formation (0.39 inches), outperforming the initial formulation and the zeolite–XG mixture without chemical bonding. Conversely, the grafting method failed to form stable viscosity or mud cake under HPHT conditions, resulting in extreme fluid loss. The combination of zeolite–XG without integration also failed to prevent mud cake cracking under pressure. The findings indicate that mixing XG and zeolite provides synergistic improvements in thermal performance, while grafting reduces rheological properties due to polymer stiffness and loss of solubility. Overall, zeolite enhances filtration control only if the viscosifier remains structurally stable.